Organic Carbon Supply and Metabolism in a Shallow Groundwater Ecosystem

Abstract

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Nutrient dynamics, transfer and retention along the aquatic continuum from land to ocean: towards integration of ecological and biogeochemical models

“…However, no straightforward insight exists on the role of DOC in groundwater denitrification. Siemens et al (2003) concluded that soil DOC is not an important electron donor in denitrification, whereas Starr and Gillham (1993) and Baker et al (2000) concluded the opposite. The redox reactivity of DOC thus appears to be location-specific, which is in line with the general observation that the biodegradability and composition of DOC in pore water varies (Qualls and Haines, 1992;Artinger et al, 2000;Maurice et al, 2002).…”

Origins and bioavailability of dissolved organic matter in groundwater

“…High DOC loading in groundwater can also lead to production of carcinogenic disinfection byproducts during drinking water treatment (Singer 1994;Chomycia et al 2008). Groundwater DOM also serves as a source of carbon and energy for heterotrophic metabolism and drives the bioremediation of many contaminants (Hendriksen et al 1992;McCarty 1997;Baker et al 2000).…”

“…More recent studies indicate surface plant litter and soil are important sources of DOM in groundwater (Baker et al 2000;Kalbitz et al 2000). Surface precipitation drives the transport of DOM through the soil column to the saturated zone.…”

Individual and population indicators of Zostera japonica respond quickly to experimental addition of sediment-nutrient and organic matter

“…It may be because organic matter can induce sediment redox in the conditions of nutrient loading, which reduces the absorption of seagrass roots to N, especially nitrate available forms by denitrification from bacterial metabolism (Peralta et al, 2003;Udy and Dennison, 1997b;. In the conditions of higher nutrient loading, denitrification requires a supply of organic matter as energy source (Seitzinger and Nixon, 1985 and its references), resulting in anaerobic respiratory processes (Korom, 1992), which may conversely promote sediment denitrification (Baker et al, 2000;Zhang et al, 2012 and its references). Nutrients absorption of seagrass roots may impact on uptake of seagrass leaves to nitrogen Harlin, 1982, 1984).…”

“…Denitrification may be heterotrophic, with organic substrates as energy source, with reduced inorganic compounds such as sulfur or iron used as electron donors (Korom, 1992), which was energy source for anaerobic respiratory processes. Anaerobic environment may promote sediment denitrification (Baker et al, 2000;Zhang et al, 2012 and its references). Nutrient enrichment may further intensify the flux of organic matter to the sediment, thereby enhancing the risk of anoxia and sulphide toxicity (Borum et al, 2005;Holmer and Bondgaard, 2001;Olivé et al, 2009;Pérez et al, 2007).…”